whats with my legs?

Ok i'll start by saying im out of shape, i have a sit down office job and i dont move around a lot. There has been times where my legs cant carry me, my knees would be a tad bit weak, and if i walk up a flight of stairs, my muscles would tight up. Now i ask, is this due to lack of blood flow or just weak legs from not being active? I do have PVC's. which are skipped beats, but been told by the cardios not to worry even tho they are frequent. anyone got an idea?

I do get dizzy sometimes, but i do have bad sinus, im always stuffy and cant breath, as far as circulation goes, if i had poor circ, it would be active all over my body, not just my legs, but i only ever feel them in my legs.

Now lets talk gravity, when i hold my arms over my head all the way up and drop them down, it feels like blood is rushing down, im guessing thats just cause gravity right?

No, poor circulation will not be felt the same all over the body. Legs and feet are farther from the heart. Blood can pool in the legs and feet when it can not be circulated sufficiently to keep it moving. Pressure from chair on back of legs can help reduce circulation to the legs/feet. Pressure in the groin area from sitting will reduce circulation to the legs/feet. Constipation can also interfer with circulation to the legs/feet.

No, it is not just gravity that makes arms feel like that.

Lack of exercise will definitely play a part in legs feeling strained when going up stairs. Lack of oxygen to vital organs can also do the same thing. Make sure you are breathing right. Check out info on hyperventilation and hiden hyperventilation. Yes, we can hyperventilate and not realize it, I did for 10 years before finding a doctor who was aware of this condition and diagnosed my problem. When we hypereventilate the red carpusles cannot release oxygen to vital organs without a balance of carbon dioxide (CO2). If the vital organs do not have enough oxygen then rest of the body will be deprived also. Vital organs will not be able to work properly. The dizziness I experienced was due to lack of oxygen. Try taking deep inhales and very slow exhales off and on during the day and see if it helps your situation.

Be sure and to get up from sitting and move about off and on during the day. It is so easy to get comfy and stay put in a chair, but, we need to get up and move or suffer the consequence.

so basically its me sitting down all the time that it pools up and when i walk great distances it feels weak? That plus that i dont walk enough....and what can cause the arm thing? when i hold it up a certain way and drop it down it just feels funny...

All i know is that my pvcs dont cause bad circulation.

But i do have breathing problems, im always really stuffy, all year round, i think i have issues with my sinus.